1. Technical Field
The present invention relates to a heat-releasing printed circuit board and a semiconductor chip package.
2. Description of the Related Art
The demands in current printed circuit boards are closely related to the trends of faster performance and higher densities in the electronics market, and to satisfy such demands, the printed circuit board faces several tasks, such as providing finer circuits, superior electrical properties, higher reliability, higher signal transfer speeds, and greater functionality, etc.
In particular, in a device such as a mobile phone, server, network, etc., which provides faster speeds and higher power consumption while being implemented in a higher density and smaller size, efficient heat release is becoming an important issue for improving product reliability and preventing malfunctions. This is because high temperatures in a semiconductor chip can be a major cause of errors such as malfunctioning and halting in a device.
Methods in the related art for lowering the temperature of a semiconductor chip include a method of installing a heat sink over the semiconductor chip that emits high levels of heat, and a method of operating a cooling fan to force out the large amounts of heat.
FIG. 1 is a cross-sectional view of a semiconductor chip package according to the related art. Referring to FIG. 1, a semiconductor chip 104 is mounted on a printed circuit board 102 by way of solder bumps 106, etc., and an underfill is injected between the semiconductor chip 104 and the printed circuit board 102 to increase the adhesion between the semiconductor chip 104 and the printed circuit board 102. After the semiconductor chip 104 is mounted on the printed circuit board 102, a molding material 108 is coated on which encapsulates the semiconductor chip 104. Also, solder balls 110 are coupled on, and the semiconductor chip 104 package is mounted on the main board by a flip chip method, etc.
Looking at the path through which the heat generated in the semiconductor chip travels, in a semiconductor chip package according to the related art, heat is generated in the semiconductor chip due to the operation of the product in which the semiconductor chip package is equipped, and this heat travels through the solder bumps and the circuits of the board to the solder balls connected to the main board. This path of heat flow does not efficiently release the high levels of heat generated in the semiconductor chip and board. As such, in the related art, heat-releasing vias penetrating the printed circuit board are formed in the joint portions between the semiconductor chip and the printed circuit board to reduce the path of heat flow, or a metal core is inserted within the printed circuit board to release heat from the sides of the printed circuit board.
However, the insulation material of the printed circuit board is generally very low in thermal conductivity, and hence acts as a large resistance to the movement of heat, hindering efficient heat release.
Also, whereas effective heat release requires heat emission in all directions of the printed circuit board, the solder resist coated on the outermost layers of the printed circuit board is also low in thermal conductivity, making it difficult to efficiently release the heat generated in the board.
Moreover, the molding material encapsulating the semiconductor chip also has a low thermal conductivity, so that the heat generated in the semiconductor chip is released only through the printed circuit board, for inefficient heat release.